Growth Of Population

( Originally Published 1915 )

MASS is a factor in the survival of a social group. Other things being equal, that society will stand the best chance of surviving which has the largest population. Moreover, the larger the mass of a given group the greater can be the industrial and cultural division of labor in that group. Hence, other things being equal, a large population favors the growth not only of a higher type of industry, but also of a higher type of culture or civilization in a given society. The questions which center around the growth of population, therefore, are among the most important questions which sociology has to deal with.

The growth of population is, of course, more or less indirectly connected with the family life, since the growth of population in the world as a whole is dependent upon the surplus of births over deaths. But population has so long been looked at as a national question that perhaps it will bd best to study it from the standpoint of the national group. The population of modern national groups, the influences which augment and deter the growth of the population of these groups, and the laws of population in general, will be what will concern us in this chapter.

Population Statistics of Some Modem Nations. — The following table of statistics will show the status of the populations of the largest nations of Europe and America in the nineteenth century.

This table shows, that while the population of nearly all of these nations has increased rapidly within the nineteenth century, that the increase is relatively unequal in some cases. If we project Russia's increase of population to the year 2000 A.D., we shall find that its probable population will be in the neighborhood of 300,000,000; Germany's probable population, say 167,000,000; Great Britain and Ireland's probable population, 135,000,000; while France's probable population in the year two thou-sand, if it continues to increase only at its present slow rate, will be but 45,000,000. While these forecasts of population cannot be considered certain in any sense, still they are sufficient to show that the growth of modern nations in population is relatively unequal. Inasmuch as the mere element of numbers is one of the greatest factors for the future greatness of any nation, this is a highly important matter. A nation of only 40,000,000 a century hence, it is safe to say, will be no more important than Holland and Belgium are now. On the other hand, it is very probable that a century hence the civilized nations that lead in population will also lead in industrial and cultural development. Many other factors, of course, enter into the situation, but the factor of mere numbers should not be neglected, as all practical statesmen recognize.

A century hence it is probable that the population of continental United States will be about 300,000,000. It would be considerably more than this if the present annual rate of increase were to continue, but inasmuch as that is not likely, an estimate of 300,000,000 is sufficiently high.' We have already seen that it is probable that Russia's population may equal 300,000,000 by the year 2000. It seems probable, therefore, that the United States and Russia may be the two great world powers a century hence, particularly if Russia emerges from its present social and political troubles and takes on fully Western civilization, while the other nations may tend to ally themselves with the one or the other of these great world powers. Of course, China is the X— the unknown quantity — in the world's future. Should its immense population become civilized and absorb Western ideas, this would certainly bring into the theater of the world's political evolution a new and important factor.

The population and vital statistics of the various civilized countries show: —

(1) The population of all civilized countries, with one or two exceptions, has been increasing rapidly since the beginning of the nineteenth century. Previous to that time we have no statistics that are reliable, but it seems probable that the population of Europe stood practically stationary during the Middle Ages and increased only slowly down to the nineteenth century; but during the nineteenth century the population of the leading industrial nations has increased very rapidly. This is due primarily, without doubt, to improved economic conditions, which has made it possible for a larger population to subsist within a given area. Back of these improved economic conditions, however, has been increased scientific knowledge in ways of mastering physical nature, and accompanying them has been a very greatly decreased death rate, due in part at least to the advance of medical science.

(2) This increase in population has been due, not to an increase in birth rate, but to a decreased death rate. During the nineteenth century the death rate decreased markedly in practically all civilized countries. As we have already noted, this is due primarily to improved living conditions, particularly in the food, clothing, and shelter for the masses, but it has also been due in no small part to the advance in medical science, and especially that branch of it which we know as " public sanitation." Because the death rate decreases with improved material, and probably also with improved moral conditions, it is a relatively good measure, at least of the material civilization or progress of a people. We may note that the death rate is measured by the number of deaths that occur annually per thousand in a given population. The death rate of the countries most advanced in sanitary science and in industrial improvement apparently tends to go down to about fifteen or sixteen per thousand annually.

(3) The birth rate of civilized countries has also fallen markedly during the nineteenth century, especially during the latter half. On the whole, this is a good thing. The birth rate should decrease with the death rate. This leaves more energy to be used in other things; but when the birth rate falls more rapidly than the death rate or falls beyond a certain point, it is evident that the normal growth of a nation is hindered, and even its extinction may be threatened. While an excessively high birth rate is a sign of low culture on the whole, on the other hand an excessively low birth rate is a sign of physical and probably moral degeneracy in the population. When the birth rate is lower than the death rate in a given population, it is evident that the population is on the way to extinction. In order that a birth rate be normal, therefore, it must be sufficiently above the death rate to provide for the normal growth of the population. On the whole, it seems safe to conclude that we have no better index of the vitality of a people, that is, of their capacity to survive, than the surplus of births over deaths. Such a surplus of births over deaths is also a fairly trustworthy index of the living conditions of a population, because if the living conditions are poor, no matter how high the birth rate may be, the death rate will be correspondingly high, and the surplus of births over deaths, therefore, relatively low.

Vital statistics are, therefore, an indication of more than the mere health or even the material condition of a given population. Probably there are no social facts from which we may gather a clearer insight into the social conditions of a given population than vital statistics.

Without going into the vital statistics of modern nations in any detail, the following table of birth rates and death rates will serve to illustrate the decrease in the death rates and, the birth rates of the three leading European nations, the birth rate being computed the same as the death rate, that is, the number of births per thousand annually of the population.

From the above table it is evident that while birth rates and death rates have been declining in all civilized peoples, the decline has been unequal in different peoples. Both England and Germany in the above table show still a good surplus of births over deaths; in the case of England in 1904 this surplus being 11.8 per thousand of the population annually, while in the case of Germany it was 15.6. In the case of France, however, the surplus of births over deaths for a number of years has been very insignificant, and in the year 1907 there were actually about 20,000 more deaths than births in all France (773,969 births against 793,889 deaths). France's population has, therefore, been practically stationary for a number of years, while within the last year or two it seems to be actually declining.

The causes of the stationary population of France are probably mainly economic, although all the factors which influence the family life in any degree must also influence birth rate. For a number of years the economic conditions of France have not been favorable to the growth of a large population, and at the same time the law necessitating the equal division of the family's property among children has tended to encourage small families. Unquestionably, however, other factors of a more general social or moral nature are also at work in France as well as in all other populations that are decreasing in numbers.

The Decrease in the Native White Stock in the United States. Certain classes in the United States also show a very slight surplus of births over deaths and in some cases absolutely declining numbers. In general the United States Census statistics seem to indicate that the native white stock in the Northern states is not keeping up its numbers. This is suggested by the decreasing size of the average family in the United States. The average size of the family in the United States in 1850 was 5.6 persons; in 1860, 5.3; in 1870, 5.1; in 1880, 5.0; in 1890, 4.9; and in 1900, 4.7. Moreover, if we include only private families in 1900, the average size of the family was only 4.6. Thus, between 185o and 1900 the size of the aver-age family in the United States decreased by nearly one full person. This decrease is most evident in the North Atlantic and North Central states. In Maine, Vermont, and New Hampshire, for example, the average size of the family in 1900 was 4.1 persons.

Moreover, the vital statistics kept by the state of Massachusetts for a number of years show conclusively that the native white stock in that state is tending to die out. In 1896, for example, in Massachusetts the native born had a birth rate of only 16.58, while the foreign born had a birth rate of 50.40. Again, the following table of birth rates and death rates for 1890 in the city of Boston 1 for the native born and sections of the foreign born shows conclusively that the native-born element is not keeping up its numbers :

It is evident from this table that the foreign born are increasing in Boston very rapidly in numbers through birth, while the native born are apparently not even holding their own. The high birth rate of the foreign born is, of course, in part to be explained through the fact that the foreign-born population is made up for the most part of individuals in the prime of life, that is, in the reproductive age. Nevertheless, while this explains the excessively high birth rate of some of these foreign elements, it does not explain the great discrepancy between their birth rate and that of the native born. If the present tendencies continue, it is apparently not difficult to foresee a time in the not very distant future when the old Puritan New England families will be replaced in the population of Boston entirely by the descendants of recent immigrants.

Moreover, so far as vital statistics concerning different classes can be gathered in the northern tier of the states, practically everywhere the same tendencies are manifest, that is, everywhere we find the native-born white population failing to hold its own alongside of the more recent immigrants. Apparently, therefore, we must conclude that the birth rate in the native whites in the United States is declining to such an extent that that element in our population threatens to become extinct if present tendencies continue. Only the Southern whites present an exception to this generalization. The Southern white people, from various causes not well understood, — partially, perhaps, from family pride, partially, perhaps, from racial instinct, but even more probably on account of certain economic conditions, — keep up their numbers, increasing more rapidly even than the negro population which exists alongside of them.

Causes of the Decrease in Birth Rate in the Native White Stock in the United States. What, then, are the causes of this decrease in the birth rate of the native white stock in the United States? It is worth our while to inquire briefly into these causes, for they illustrate the factors which are at work in favoring or deterring the growth of population.

(1) Economic conditions are without doubt mainly at the bottom of the decreasing birth rate in the native white American population. Certain unfavorable economic conditions have developed in this country of recent years for this particular element; especially have higher standards of living increased among the native white population in the United States more rapidly than their income. This has led to later marriages and smaller families. Again, more intense competition along all lines has forced certain elements of the native stock into occupations where wages are low in comparison with the standard of living. This has, perhaps, especially come about through the increased competition which the foreign born have offered to the native white element. The foreign born have taken rapidly all the places which might be filled by unskilled labor and many of the places filled by skilled labor. The native born have shrunk from this competition and have retired for the most part to the more socially honorable occupations, such as clerkships in business, the professions, and the like. In many of these occupations, however, as we have already said, the wages are low as compared with the standards of living maintained by that particular occupational class; hence, as we have already said, later marriages and fewer children. Rising standards of living and rising costs of living have, therefore, impinged more heavily upon the native born than upon the foreign born. It is difficult to suggest a remedy for this condition of affairs. No legislator can devise means of encouraging a class to have large families when by so doing that class would necessarily have to sacrifice some of its standards of living. However, it may be that the native born can be protected to some extent from the competition of the foreign born through reasonable restrictions upon immigration, and it may also be that unreasonable advances in standards of living may be checked, but both of these propositions seem to be of somewhat doubtful nature.

(2) No doubt the pressure of economic conditions is not responsible for small families in some elements of the native white population in the United States, for often-times the smallest families are found among the wealthy, among whom there could be no danger of a large family lowering the standards of living or pressing upon other economic needs. We must accept as a second factor in the situation, therefore, the inherent selfishness in human nature which is not willing to be burdened with the care of children. In other countries, and apparently in all ages, the wealthy have been characterized by smaller families than the poor. The following table from Bertillon, 1 showing the number of births per thousand women between fifteen and fifty years of age in Paris, Berlin, and London among the various economic classes, shows conclusively that it is not altogether the pressure of economic wants which leads to the limiting of a population:

(3) Besides economic conditions and individual selfishness we must unfortunately add another cause of de-creasing birth rate in our population which has been definitely ascertained, and that is vice. Vice cuts the birth rate chiefly through the diseases which accompany it. About 20 per cent of American marriages are childless, and medical authorities state that in one half of these childless marriages the barrenness is due to venereal diseases. Ac-cording to Dr. Prince A. Morrow, in his Social Diseases and Marriage, 75 per cent of the young men in the United States become impure before marriage. This serves to disseminate venereal diseases among the general population, especially among innocent women and children. The consequence is, on the one hand, a considerable number of sterile marriages and on the other hand a high infant mortality. It need not be assumed, as we have already said, that vice is more prevalent to-day than in previous generations, but on account of the conditions of our social life diseases which accompany vice are now more widely disseminated than they have been at any time in our previous history; therefore, even the physical results of vice are different to-day than they were a generation or more ago.

(4) Education has been alleged as a cause of decreasing birth rate in the native white American stock. This, however, is true only in a very qualified sense. While it is a fact, as collected statistics have shown, that if Harvard and other universities depended on children of their alumni for students their attendance would actually de-crease in numbers, it is not true that college graduates have had a lower birth rate than the economic and social classes to which they belong. So far as statistics have been collected, indeed, they seem to indicate that the wealthy uneducated are producing fewer children than the educated classes who associate with them. The influence decreasing the birth rate among the educated is, therefore, not education itself, but the high standards of living and the luxury of the classes with whom they associate.

On the other hand, the higher education of women seems to be, down to the present time, operating as a distinct influence to lessen the birth rate among the educated classes for the reason that apparently a majority of educated women do not marry. The higher education has not yet gone far enough, however, to give us any definite facts with which to judge what the ultimate effect of woman's higher education will be. If the higher education of woman is going to lead to a large per cent of the best and most intellectual women in society leading lives of celibacy, then, of course, ultimately the higher education of woman will be disastrous to the race. But probably the relative infrequency of marriage among women who are college graduates is a transitory phenomenon due to the fact that neither women nor men are as yet adjusted to the higher education of women.

(5) Some phases of the " woman's movement " have without doubt tended to lessen the birth rate in certain sections of American society. Some of the leaders of the woman's movement have advocated, for example, that women should choose a single life, while others have advocated that families should not have more than two children. Mrs. Ida Husted Harper, indeed, has gone so far as to claim that if families would have but two children this would be a cure-all for many social troubles. Indeed, this ideal of two children in the family has been so widely disseminated in this country that it is often spoken of as the " American Idea. Of course, such teachings could not be without some effect. Without attempting to reply to the advocates of this theory of but two children to a family, it will be sufficient to remark that for a population simply to remain stationary three children at least must be born to each family on the average; otherwise, if only two children are born, as one of the children is apt to die or fail to marry, the population will actually decrease in numbers. Under the best modern conditions one out of three children now born either fails to live to maturity or fails to reproduce. There must be, therefore, more than three children born to the average family for a population to grow. From the sociological point of view the ideal family would seem to be one in which from three to six children are born.

(6) Finally, not all of the childless and small families in the native American stock are due by any means to voluntary causes, or even involuntary causes of the kind that we have mentioned. There are also certain other obscure physiological causes at work producing sterility in American women. The sterility of American women is greater than that of any other civilized population, even apart from the causes which have just been mentioned. Some say this is due to physical deterioration in the native white American stock, and there are other things which seem to point in that direction. It may be, however, that this deterioration is in no sense racial, but only individual, affecting certain individuals who lead a relatively unnatural life.

Our American civilization puts a great strain upon certain elements of our population, and this strain in many cases falls even more upon the women than upon the men. The social life of the American people, in other words, is oftentimes such as to produce exhaustion and physical degeneracy, and this shows itself in the women of a population first of all in sterility. It is evident that the remedy for this cause is a more natural and more simple life on the part of all, if it is possible to bring this about.

Thus, the causes which influence birth rate are evidently very complex. In the main they are doubtless economic causes among all peoples, but there is no reason to believe that these economic causes act alone in determining birth rate, nor is there any reason to believe that the other psychological and biological causes may be in any way derived from the economic. So far as we can see, then, industrial conditions are mainly responsible for the lessened birth rate in the native white American stock. But mingled with these industrial conditions, operating as causes, are certain psychological (or moral) and biological factors that have to be considered as in the main independent. It is furthermore evident that the causes which lead to the decline and extinction of any population, whether civilized or uncivilized, are complex. All efforts to explain the extinction of peoples of antiquity, or modern nature peoples, such as the North American Indians and the Polynesians, through any single set of causes, must be looked at as unscientific. It can readily be shown that in all these cases the causes of the decline of the birth rate and the ultimate extinction of the stock are numerous and are not reducible to any single set of causes.

Causes which Influence the Death Rate. Before we can fully understand the causes of the growth of a population, that is, of the surplus of births over deaths, we must under-stand something also about the things which influence the death rate as well as the things which influence the birth rate, because, let it be borne in mind, the growth of a given population (excluding immigration always) is due to the combined working of these two factors.

Within certain limits the death rate is more easily con-trolled than the birth rate. It is very difficult for society deliberately to set about to increase the birth rate, but it is comparatively easy for it to take deliberate measures to decrease the death rate, because all individuals have a selfish interest in decreasing the death rate; but the increase of the birth rate does not appeal to the self-interest of individuals. Modern medical science, as we have seen, has done much to decrease the death rate in civilized countries, and it promises to do even more. Fifty years ago a death rate of fifty or sixty per thousand population in urban centers was not unusual, but now a death rate of thirty to forty in a thousand in the same communities is considered an intolerable disgrace, and the time will shortly come, no doubt, when even a death rate of twenty per thousand of the population will be considered disgraceful to any community. As we have already seen, the normal death rate of the most enlightened European and American communities tends to establish itself around fifteen or sixteen.

Of course the sanitary and hygienic conditions which influence the death rate are so numerous that we cannot enter into and discuss them. We can only mention some of the more general social influences which are often overlooked and are of particular interest to the sociologist.

(1) The effect of war upon the death rate, particularly of the victorious, is not so great as many people suppose. Considerable wars are apparently often waged without very greatly increasing the number of deaths in a given population. This is, however, only true, as has already been said, of the victorious side. With the defeated it is far different. The death rate among the defeated in a modern war is oftentimes very greatly raised, but this is due not so much to the large number killed in battle as to the fact that the defeated have their territory invaded, their industries disturbed, and their general industrial and living conditions depressed. The vital statistics of France and Germany in the Franco-Prussian War of 187o–1871 illustrate this point. In Germany the death rate in 1869, the year before the war, was 28.5; in 187o, the first year of the war, 29; and in 1871, the culminating year of the war, 31. These figures include the armies in the field. For France, however, the defeated party, the figures were far different. In 1869 the death rate in France was 23.4; in 1870, 28.3; in 1871, 34.8. Thus, while Germany had its death rate increased by the Franco-Prussian War merely 2.5 per thousand of the population, France had its death rate increased 11.4. From this it is plain that it is the economic disturbances which accompany war, and particularly those which are manifest among the defeated, which cause a very large part of the higher death rate.

(2) As already implied, then, economic depression exercises a very considerable influence upon death rate, particularly when economic depression causes very high prices for the necessities of life and even widespread scarcity of food. This cause produces far more deaths in modern nations than war. The doubling of the price of bread in any civilized country would be a far greater calamity than a great war. While modern civilized peoples fear famine but little, there are many classes in the great industrial nations that live upon such a narrow margin of existence that the slightest increase in the cost of the necessities of life means practically the same as a famine to these classes. Statistics, therefore, of all modern countries, and particularly of all great cities, show an enormous increase in sickness and death among the poorer classes in times of economic depression.

(3) Climate and season are rather constant factors in the death rate of all communities. The rule here is that in northern countries the death rate is higher in winter, while in southern countries and in great cities the death rate is higher in summer. Taking 100 as an arbitrary standard, in Sweden in February deaths rise to 113, in August they go down to 79; while in Italy in February deaths are at 106 as compared with the standard, and in August at III, the period of minimum death rate in Italy being in the spring and autumn. In a great city like Berlin, if 100 be taken as the standard, deaths are 88 in February and 144 in August, owing very largely to the higher death rate of children in the summer months in great cities.

(4) The biological fact of sex also influences death rate. Males in general are shorter-lived than females. This is in part due to the fact that in human populations men are more exposed to the dangers of industry in earning a livelihood, while women are more secluded in the home. But this does not explain entirely the discrepancy in the death rate of the two sexes, for boy babies under the same conditions die more frequently than girl babies. As we have already seen, the female organism is the more stable, biologically, and hence females, while having less physical strength, have more vitality than males. In Great Britain the death rate (1872-1880) for the males was 22.7 per thousand of the male population annually, while the death rate for the females was 20.2 per thousand of their population annually.

(5) Conjugal condition is also a factor which affects death rate. The differences between the death rates of the married and unmarried have long been noted. The following table of the death rates of males and females of different conjugal classes between the ages of forty and fifty years (in Germany, 1876—1880), taken from Professor Mayo-Smith's Statistics and Sociology, illustrates this:

It will be seen from these figures that the death rate among the single is in all the more advanced years of life higher than among the married. The probable explanation of this, however, is not that the married state is better physiologically, as has been so often claimed, but that it is better socially. These figures are a testimony, in other words, to the social advantages of the home. Single persons, particularly in the more advanced years of life, who are with-out homes, are more liable to fall sick, and when sick are less liable to receive proper care. That these figures show the great social advantage of the home in preserving life is evident from the fact that among the widowed males, whose homes have been broken up, the death rate is higher even than among the single males. Moreover, in interpreting such statistics we must bear in mind that the unmarried in the higher ages of life are made up very often of those who are relatively abnormal, either physically or mentally, that is, of the biologically unfit. Inasmuch as the single persons include many of this class, and also lack the comforts of home, it is not surprising that the death rate is much higher among them.

(6) Infantile mortality is one of the most interesting phases of vital statistics. We have already said that the death rate is a good rough measure of a people's civilization. Even more can we say that the death rate among children, particularly those under one year of age, is an index to a people's sanitary and moral condition. Taking the world as a whole, it is still estimated that one half of all who are born die before the age of five years. This represents an enormous waste of energy. Even in many of the most civilized countries the death rate among children, and especially among infants under one year of age, is still comparatively high. Most of this death rate is unnecessary, could be avoided, and, as we have already said, represents a waste of life. Dr. Newman gives the following statistics for different civilized countries for the
ten-year period of 1894-1903. These statistics, we may. note, are based on the percentage of deaths among children under one year of age. and not upon the one thousand of their population. In Russia, 27 per cent of all children born during the ten-year period of 1894–1903 died the first year; in Germany, 19.5 per cent; in Italy, 17 percent; in France, 15.5 percent; in England, 15 percent; in Ireland, 10 percent; in Norway, 9.4 per cent; in New Zealand, 9.7 percent; while in the United States in 1900, according to the census, 16.2 per cent of all children born in the registration area died the first year.

The Laws of the Growth of Population. — Can the growth of population be reduced to any principle or law? This is a problem which has puzzled social thinkers for a long time. Many have thought that the growth of population can be reduced to one or more relatively simple laws, but we have seen from analyzing the statistics of birth rate and death rate that this is hardly probable. A formula that would cover the growth of population would have to cover all of the variable causes influencing birth rate and death rate and so entering into the surplus of births over deaths. It is evident that these causes are too complex to be reduced to any such formula among modern civilized peoples. In the animal world and among uncivilized peoples, however, conditions are quite different, and the growth of population is regulated by certain very simple principles or laws. Thus it is probable that for centuries before the whites came, the Indians of North America were stationary in their population, for the reason that under their stationary condition of culture a given area could support only so many people. In conditions of savagery, and even of barbarism, therefore, we can lay down the principle that population will increase up to the limit of food supply, will stop there and remain stationary until food supply increases. This is the condition which governs the growth of the population of all animal species, and, as we have already said, of the savages and barbarians among the human species. But among civilized men who have attempted the control of physical nature, and to some extent even the control of human nature, many other factors enter in to influence both birth rate and death rate, and so the growth of the population.

Nevertheless, many social thinkers of the past have conceived, as has already been said, that the growth of population might be reduced to very simple and definite laws. Among the first who proposed laws governing population was an English economist, Thomas Robert Malthus, whose active career coincides with the first quarter of the nineteenth century. In 1798 Malthus put forth a little book which he entitled An Essay on the Principle of Population as it affects the future improvement of society. This essay went through numerous editions and revisions, and in it Malthus elaborated his famous economic theory of the growth of population. Inasmuch as this theory of Malthus has been the storm center of sociological and economic writers for the past one hundred years, it is worth our while to note very briefly what Malthus's theory was, and why it is inadequate as a scientific statement of the laws governing the growth of population.

Malthus's Theory of Population. In the first edition of his essay Malthus contended that population tends to increase in geometric ratio, while food at best will increase only in arithmetical ratio; and that this means that constant discrepancies between population and food supply would appear, with the result that population would have to be cut down to food supply. Later Malthus saw how crude this statement of his theory was and abandoned any attempt at mathematical statement, presenting substantially the following theory: (I) Population is necessarily limited by food; (2) Population always increases where food increases and tends to increase faster than food; (3) The checks that keep population down to food supply may be classified as positive and preventive. Positive checks are those which increase the death rate, such as famine, poverty, vice, disease, and the like. Preventive checks are those that decrease the birth rate, such as late marriage and prudence in the birth of children. Inasmuch as Malthus believed that the positive checks must always operate where the preventive checks did not, he advocated the use of the preventive checks as the best means to remedy human misery. The inherent tendency of population to outstrip food supply, Malthus believed to be the main source of human misery in all of its forms.

Criticisms of Malthus's Theory. (I) It is evident that Malthus's theory applies only to a stationary society, that is, a nonprogressive society, because in a progressive society human invention and, therefore, food supply, may far outstrip any increase of population. This has been the case in practically all civilized countries during the nineteenth century, where improvements in machinery and agriculture have greatly increased the food supply. If it be replied that this increase of food is but temporary,
and that sooner or later Malthus's theory must operate, then it may be said, on the other hand, that as yet we see no limit of man's mastery over nature, and that apparently we are just entering upon the stage of material progress. Moreover, so far as any given country is concerned, wealth is potential food supply, and in the United States during the last fifty years wealth has increased four times as fast as the population. Malthus, of course, did not foresee the inventions and agricultural progress of the nineteenth century. Still, it is evident that his theory is a static one and cannot be made to apply to any progressive society.

(2) Similarly, the theory makes no allowance for the increased efficiency which may come with increased population, because increase of population makes possible better cooperation. As we have already seen, cooperation and division of labor in a society depend upon the size of the group to a certain extent, that is, the larger the group there is for organization the better can be the organization and division of labor in that group. Every increase of population, therefore, opens up new and superior ways of applying labor; and cooperation and the division of labor make it possible for men to do more as a group than they could possibly accomplish working as individuals. Improved means of cooperation, therefore, operate very much the same way in human society in controlling nature as new inventions.

(3) The theory of Malthus makes no allowance for the general law of animal fertility, which is that as the rate of individual evolution increases the rate of reproduction decreases. Of course, Malthus's theory antedates this law of animal fertility, which was first stated by Herbert Spencer. Some scientists declare that this law does not apply within the human species, and it must be admitted that it is not yet certain that it does. As we have already seen, however, the lower and less individualized classes in human society reproduce much more rapidly than the upper or more individualized classes. Increase of food supply, of wealth, and so on, does not necessarily mean increase of population, and the fatal error in Malthus's theory is that he assumes that wherever food increases population always increases also.

(4) The overpopulation which Malthus feared, so far from being an evil, has been shown by the labors of Darwin to be the condition essential to the working of the process of natural selection in the human species. Overpopulation, at least until artificial selection arrives, is not an evil, but a good in human society. Without it there would not be sufficient elimination of the unfit in human society to prevent wholesale social degeneration. Even with artificial selection, however, some overpopulation would be necessary for the working of any scheme of selection. We must conclude, then, that Malthus's theory, either as an explanation of the growth of modern populations or as an implied practical ethical doctrine, is of no value whatever.

This is not saying, of course, that Malthus's theory may not have some elements of truth in it. Undoubtedly Malthus's theory does apply to stationary, nonprogressive peoples, like savages and barbarians in certain stages of culture, and also perhaps to certain classes in modern society who fail to participate in modern social progress. But these lower classes or elements in human society are constantly decreasing, especially in America, where the tendency to individual improvement is so marked. Again, Malthus's theory, so far as it depends upon the economic law of diminishing returns in agriculture, has also certain elements of truth in it, and in so far as it merely asserts that the struggle for existence in human society is, in the last analysis, a struggle for food. Finally, Malthus meant his theory chiefly as a criticism of socialistic and communistic schemes, which would equalize wealth and do away with competition in society. Unquestionably any such scheme to equalize wealth and do away with competition in society would result in the enormous increase of the lower and more brutal element of society — those that have not yet participated in modern culture. Malthus's theory as a criticism of socialistic schemes that would do away with competition (this, however, does not apply to modern scientific socialism) is unquestionably as good today as when it was written.

Most modern economists and sociologists recognize the failure of Malthus to formulate a successful theory of population, and so many have attempted to form theories independent of Malthus; but it must be said regarding most of these attempts that they have succeeded no better than Malthus. For example, a French economist and sociologist, Arsene Dumont, has formulated the theory that society is like a sponge so far as population is concerned, that it will take up just as many new individuals as it has industrial room for, and that population will in all cases expand to meet these increased economic opportunities. Dumont's theory is that population will increase 'so far as what he calls the power of social capilarity extends. The law of population is, then, the capilarity of society. Where there are new economic opportunities population will increase; where there are no new economic opportunities there will be no increase. France has no new economic opportunities, so the population will not increase. The same is true of certain classes in the United States. This theory tries to make population depend even more entirely upon economic conditions than Malthus's theory. At first it appears more plausible than Malthus's theory, but this is probably because it is more vague. Economic influences are powerful influences, as we have already seen, in determining the growth of a population, but they are not the only ones. The factors which make up the surplus of births over deaths are so complex that they cannot possibly be lumped together and called collectively economic conditions. Dumont's theory of the growth of population has no more scientific value than Malthus's theory.

In conclusion, we may say that we are unable to formulate any laws of population which are worthy of the name of laws as yet, and it seems probable that, while we may understand clearly enough the factors which enter into the growth of population, we shall never be able to reduce these factors to a single formula or law. Social phenomena are too complex, we may here note, to reduce to simple formulas or laws as physical phenomena are reduced. Indeed, it is doubtful whether laws exist among social phenomena in the same sense in which they exist among physical phenomena, that is, as fixed relations among variable forces. Human society has in it another element than mechanical causation or physical necessity; namely, the psychic factor, and this so increases the complexity of social phenomena that it is doubtful if we can formulate any such hard and fixed laws of social phenomena as of physical phenomena. This is not saying, however, that social phenomena cannot be understood and that there are not principles which are at work with relative uniformity among them. It is only saying that the social sciences, even in their most biological or physical aspects, cannot be reduced to the same exactness as the physical sciences, though the knowledge which they offer may be in practice just as trustworthy.